1. Field of the Disclosure
Embodiments disclosed herein relate generally to bend restrictor devices for flexible pipes and umbilicals. In particular, embodiments disclosed herein relate to a bend limiting stiffener installed on umbilicals and flexible pipes.
2. Background Art
Flexible pipes, flowlines, power cables, and umbilicals are usually connected to a rigid structure such as a subsea riser base, pipeline end manifold (PLEM), wellhead or other structure. To prevent these pipes from overbending at the interface between flexible and rigid structures, bending restrictors may be installed on the pipe. Bending restrictors, or bend limiters, are devices used where static (or quasi static) loads act on a pipe, while bend stiffeners are separate devices that act to resist dynamic loads. The bending restrictor usually includes a number of interlocking elements which articulate when subjected to an external load and lock together to form a smooth curved radius known as the locking radius. The locking radius may be chosen to be equal to or greater than the minimum bend radius of the pipe. Once the elements have locked together the bending moment present is transferred into the elements and back through an interface between the flexible and rigid structure, thereby protecting the pipe from potentially damaging loads.
The installation of bend stiffeners and limiters may be very costly, as current technology allows for the units to be installed only during the umbilical manufacturing process. Because of this, the larger umbilicals now require limiters of immense inner diameter to fit over the terminal end of the umbilical. Because of this, there are large gaps between the outer diameter of the umbilical and the inner diameter of the limiters (i.e., an annulus space).
Accordingly, there exists a need for a device capable of providing bend limiting and stiffening characteristics along with rapid installation.